1. Field of the Invention
The present invention generally relates to chiral compounds. More particularly, the present invention relates to chiral binaphthyl compounds used in the liquid crystal compositions.
2. Description of Related Art
For the commonly used liquid crystal display (LCD) devices, various types of LCD devices can be classified based on the operation mode of liquid crystals or the driving mode, including twisted nematic (TN) display devices, super twisted nematic (STN) display devices, surface-stabilized cholesteric texture (SSCT) display devices, polymer-stabilized cholesteric texture (PSCT) display devices and thin film transistor (TFT) display devices.
The displaying quality of the liquid crystal display devices is essential and can be evaluated by several parameters, such as voltage holding ratio (VHR) and residual direct current voltage (Vrdc). If VHR is low, the voltage applied to the liquid crystal during the frame time will be lowered, leading to decreased brightness or even hindering the normal displaying of gray level. On the other hand, if Vrdc is too large, a residual image may be generated, that is, an image retention effect after voltage application.